Apparatus for trimming wrapped objects



Aug. 25, 1953 w. F. LILLEY ET-AL v 2,649,909

' APPARATUS FOR TRIMMING WRAPPED OBJECTS- Filed Sept. 11, 1948 INVEN'TORS WILLIAM F. LILLEY JAMES E. SNYDER JOSEPH F. STALTER ATTORNEY Patented Aug. 25, 1953 APPARATUS FOR TRI 'OBJ Delaware MMING WRAPPED ECTS William F. Lilley, James E. Snyder, and Joseph F. Stalter, Akron, Ohio, assignors to Wingfoot Corporation, Akron, Ohio, a. corporation of Application September 11, 1948, Serial No. 48,848 V 6 Claims.

The present invention relates to wrapping machines and particularly to that class of machines employing a heat scalable film for the wrapping material suchas rubber hydrochloride. A particular object of the invention is to provide means for removing the surplus web of Wrapping material surrounding the article after the wrapping operation has been completed.

Another object of this invention is to provide a method for removing the surplus film of wrapping material surrounding the object by a trimming device that substantially follows the contour of the object, irrespective of the objects shape, the trimming means being controlled preferably by the contour of the article.

Another object of the invention is to provide a means of removing the surplus film of wrapping material by a heated cutting element guided to follow the contour of the object.

Various machines have been devised for wrapping articles in heat sealable film and one of these is illustrated in the Clunan Patent No. 2,340,260. In wrapping machines of this type, the objects are interposed between two layers of the film and then the layers of the film are pressed around the object and sealed together, thus completely enclosing the objects in a continuous strip of the film from which the objects have to be separated. It is, therefore, a primary object of this invention to provide a means for accomplishing this result mechanically immediately following the wrapping operation to successively separate the wrapped articles.

Other objects of this invention will appear hereinafter as the description thereof proceeds, the novel features, arrangement and combination being clearly pointed, out in the specification and in the claims-thereunto appended.

In the drawings:

Fig. 1 is a fragmentary plan view showing the trimming means in the normal inoperative position;

7 Fig. 2 is a fragmentary plan view showing the position of the trimming means at a successive stage of the trimming operation;

Fig. 3 is afragmentary plan-view showing-the position of the trimming means at a more advanced stage of the trimming operation;

. Fig. .4 is a cross-sectional view taken along the line 44 on Fig. 1; and

Fig. 5 is a cross-sectional view taken along the line5-5onFig.3. U

In Fig. 1, the strip I, comprised of two layers of wrapping material with the objects 2 interposed between, is advancing toward the trimming means consisting of coacting assemblies 3 and 4 here shown disposed on opposite sides of the path of travel of the strip l. The same reference characters indicate corresponding parts of these cutting mechanisms.

The arm 5, rotating about stationary pivot 6, mounted on plate 1, is normally held against stop 8 by tension spring 9 fastened to the arm 5 and plate I. The arm 5, as shown, is generally straight but the end is arcuately shaped inwardly toward the object to prevent the arm from contacting the wrapped object but may be any structure or shape that will prevent the arm from contacting the object. The arcuate end of arm 5 carries the follower l0, securedto and rotatable with the pin II, as shown in Fig. 4, and is nor-' mally held against stop l2 by the torsion spring 13 (Fig. 4) In assembly 3, the torsion spring l3, surrounding the pin II, is connected at its ends to the cap I 4 of the pin and the arm 5 in such manner as to rotate the follower Ill, as viewed in Fig. 1, in a counter-clockwise direction to its normal position against the stop l2. The spring [3 will allow the follower In to rotate clockwise so as to follow the contour of the object during the trimming operation but will return it to the normal position again when the trimming operation is complete. The follower IS on arm 5 of assembly'4 functions similarly but the spring [3 tends to rotate the follower In in a clockwise direction to its normal position.

The cutter l5, attached to the follower I0, is a flat narrow loop formed of closely-spaced parallel wires, even more closely spaced than shown in the drawing. These extend through the insulating material l6 and are connected to a suitable source of electrical energy (not shown) by the wire connections 11. The wires of the loop l5 are so arranged as to be substantially equidistant from the object as the follower Ill progresses along the periphery of the object 2, shown inFig.2, thus the diameter of the wire is the width of the cut in the film. When the follower I 0 is in the normal inoperative trimming position, shown in Fig. 1, the width of the cut is determined by the spacing of the sides of the loop l5. Any other form of heated cutting element maybe used, and, with certain wrapping materials, an unheated cutting element may be suf- In Figs. 1', 2, and 3, the cutters I 5 of assemblies 3 and 4 substantially follow the paths indicated by thenumerals l8 and I9, respectively. In Fig. 2, the strip i with the wrapped objects 2 and 20 interposed between its layers, is shown with the In Fig. 3;, the wrapped object 2' has been sepa-- rated from the strip 1 of wrapping material and the next object 20 is now being separated. In Fig. 3, the assembly 3 has completed its portion of the trimming operation and the assembly 4 is operative in completing its portion of the operation. Note that the cutting lines of the assemblies 3 and 4 cross so asto' completely'separate the objects from the strip. The film may be held under slight tension by any suitable means, but, as illustrated, the tension is maintained by two pairs of driven tentering'rolls- 2i and 22'; as illustrated in Figs 3. Such mechanisms, in and of themselves, are not new and it is not believed necessary to illustrate any details thereof.

In Fig. 5, the wrapped'object' fitlis beingseparated'from the strip l by the cutter l5of assembly 4, severing the strip I at sufiicient distance from the object zll'soa not to destroy theseal between the layers of the strip 5'. The follower Ill is inconta'ct with the object 20'and'the cutter Iii is extende'dt-hrougn the film.

Due to the variations. in the heights of the different objects wrapped; the location of the strip 1, relative-to the supporting member 23, as'seen in Fig; 5, will. vary so that the cutter l5 will not always be in the proper relative position to sever: the strip: I. The length ofthe cutter I5 will take care of "the' minorvariations but in orderto handle any'major variations, it is desirable thatthe position of the'cutter l5 may be adjusted so asto correspond to the position of the strip I. For example, thiscan' be accomplished by mounti'ng'the plates l of the cutting assemblies 3 and 4" for'vertic'al adjustment.

In the operation of the trimming means, as the strip I; with the object contained between its layers; progresses through the machine, the

assembly 3 of the cutting means first becomes operative asthefollower l contacts-the object 2 and the arm 5- deflects clockwise about pivot 6, aiding the follower l0 and. cutter i5 to follow the periphery o'f'the object 2 and'sever the strip 1 closely adjacent to the object without destroying the seal between thelayers. The tension spring 9' and the torsion spring I3 function so as to make the arm- 5 and follower 10 hug the periphery of the object 2 and leave-a uniform trim flash of filmadjacent to the wrapped object, the cutter l5' substantiallyfollowing the path l8. Similarly,

the assembly 4- operates to' sever the film on the opposite side of the object 2 but the arm- 5 is deflected counterclockwise about pivot Gwhen the follower l0 contacts the object and the tension spring-- 9 and the torsion spring l3 operate in areverse direction to those of assembly 3, the cutter l5 substantially following the path I91 The objects are completely separated from the continuing strip of wrapping material as illustrated by-obj act 2 in Fig. 3.

While-certain representative embodiments and details have been shown for the purpose of illustr-ating the invention; it' will'be apparent to those skilled in the art that various changes and modifications may be made therein without departing fromthe'spirit orscope of the'invention.

Having thus fully describedour invention, what we. claimand' desire to secure by Letters Patent oi the United-States is A3 trimming. mechanism adapted to be mounted adjacent a conveyor element in a wrap- .a cutting element carried by said arm and movable therewith, a stop for normally limiting the movement of saidfollower in one direction about its" pivot, and a spring normally urging said follower in a direction to bring said follower against said stop:-

2'. A device as set forth in claim 1 in which there are a pair. of. said mechanisms mounted on opposite side of the path of movement of the conveyor...

3. A. trimming mechanism adapted to be mounted adjacent a conveyor element in a wrapping machine which comprises a pivoted arm, means for normally limiting themovement of said arm in one direction about its pivot, meansfor' normally urging said arm in a direction to bring said arm against said first-mentioned mounted adjacent a" conveyor element in" a wrap-- pin machine which comprises a pivoted arm, a stop for normally limiting the movement of. said. arm in one di'rectionabout its pivot; a spring normally'urging said arm-in a direction to bring said arm against said stop, a pivoted follower on.

the end of saidarm, a heated cutting element carried by said arm and movable therewith, a stop for normally limiting the movement of said follower: in onedirection about its pivot; and a sprin normally urging said follower in a direction' to bring'said'followeragainst said stop.

5: A device as' set forth in claim 4' in which there is. a: pair of said mechanisms mounted on oppositesides of the'p'ath of. the movement of the conveyor.

6-. A device: asset forth in claim 4 in which there is a pair of said: mechanisms mounted on opposite sides. and at different positions along said path so that thepaths of the cutting elements overlap.

WILLIAM F. LILLEYI JAMES E. SNYDER. JOSEPH F. STALTER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 658,711 Forker' Sept. 25, 1900 680,927 Krom Aug. 20, 19 1 701,828- Arnold June 10, 1902 8811899 Chapman Mar. 17, 1908 1,179,493 Ba1l= Apr..l.8, 1916 1,724,208 Lewis Aug. 13, 1929 1,762,826 Lehman June 10, 1930' 1,790,048 Hutt et al Jan. 27,1931 1,813,761 Pickett July '7, 1931 2,048,684.- Carr July 28, 1936 2,232,783 Hausheer Feb. 25, 1941.

FOREIGN PATENTS Number Country Date 436,774 Germany e v Feb. 10, 1926 

